This is a fantastic post. So much of it I could relate to.
My wife and I were "best friends" for five years before getting married. We were both highly attracted to each other, but never hooked up for one reason or another. We both dated others. I heard occasional references to how good some of her boyfriends were in bed and how they were hung (usually big). We finally acknowledged our love and attraction and how we'd made ourselves and others miserable, so decided to take the plunge and get married.
Sex was good, maybe even fantastic, but I recognized that I probably couldn't give her the earthshaking climaxes her better-hung boyfriends could (at least through penetration alone). For the longest time "size" was taboo with her, although she'd been casual about the subject before. A few years ago we started opening up on the subject. It started with playful comparisons to her 7.5" dildo which we used occasionally. Now we are completely open about my cock being small and discussing the size of of her previous boyfriends.
I've always played the super-confident "alpha" male, tall, good-looking, well-built. It really was arousing opening up about my size, experiencing the sense of vulnerability that this involves. My wife can have a wicked sense of humor at times, and I sure was potentially opening myself up to this. However, being open about having a small cock and the insecurities surrounding -- something I'd always kept hidden -- this has resulted in a much greater sense of sexual intimacy between us.
It has resulted in a few surprises. Although my wife has admitted that she "physically" prefers a larger penis, she's also confessed to being extremely aroused by my having a smaller cock, that she finds its contrast to my large physique and its relative vulnerability on my part especially erotic.